From 8337e0c57345f24cf6471220e5f8a0ea21b7c1d0 Mon Sep 17 00:00:00 2001 From: Vittorio Giovara Date: Wed, 20 May 2015 00:01:37 +0100 Subject: Introduce a TextureDSP module This module implements generic texture decompression from different families (DXTC, RGTC, BCn) and texture compression DXTC 1, 3, and 5. Signed-off-by: Vittorio Giovara --- libavcodec/texturedspenc.c | 659 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 659 insertions(+) create mode 100644 libavcodec/texturedspenc.c (limited to 'libavcodec/texturedspenc.c') diff --git a/libavcodec/texturedspenc.c b/libavcodec/texturedspenc.c new file mode 100644 index 0000000000..4a387c5edc --- /dev/null +++ b/libavcodec/texturedspenc.c @@ -0,0 +1,659 @@ +/* + * Texture block compression + * Copyright (C) 2015 Vittorio Giovara + * Based on public domain code by Fabian Giesen, Sean Barrett and Yann Collet. + * + * This file is part of Libav + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include +#include + +#include "libavutil/attributes.h" +#include "libavutil/common.h" +#include "libavutil/intreadwrite.h" + +#include "texturedsp.h" + +const static uint8_t expand5[32] = { + 0, 8, 16, 24, 33, 41, 49, 57, 66, 74, 82, 90, + 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, + 198, 206, 214, 222, 231, 239, 247, 255, +}; + +const static uint8_t expand6[64] = { + 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, + 48, 52, 56, 60, 65, 69, 73, 77, 81, 85, 89, 93, + 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142, + 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, + 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, + 243, 247, 251, 255, +}; + +const static uint8_t match5[256][2] = { + { 0, 0 }, { 0, 0 }, { 0, 1 }, { 0, 1 }, { 1, 0 }, { 1, 0 }, + { 1, 0 }, { 1, 1 }, { 1, 1 }, { 2, 0 }, { 2, 0 }, { 0, 4 }, + { 2, 1 }, { 2, 1 }, { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 0 }, + { 3, 1 }, { 1, 5 }, { 3, 2 }, { 3, 2 }, { 4, 0 }, { 4, 0 }, + { 4, 1 }, { 4, 1 }, { 4, 2 }, { 4, 2 }, { 4, 2 }, { 3, 5 }, + { 5, 1 }, { 5, 1 }, { 5, 2 }, { 4, 4 }, { 5, 3 }, { 5, 3 }, + { 5, 3 }, { 6, 2 }, { 6, 2 }, { 6, 2 }, { 6, 3 }, { 5, 5 }, + { 6, 4 }, { 6, 4 }, { 4, 8 }, { 7, 3 }, { 7, 3 }, { 7, 3 }, + { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 5 }, { 5, 9 }, { 7, 6 }, + { 7, 6 }, { 8, 4 }, { 8, 4 }, { 8, 5 }, { 8, 5 }, { 8, 6 }, + { 8, 6 }, { 8, 6 }, { 7, 9 }, { 9, 5 }, { 9, 5 }, { 9, 6 }, + { 8, 8 }, { 9, 7 }, { 9, 7 }, { 9, 7 }, { 10, 6 }, { 10, 6 }, + { 10, 6 }, { 10, 7 }, { 9, 9 }, { 10, 8 }, { 10, 8 }, { 8, 12 }, + { 11, 7 }, { 11, 7 }, { 11, 7 }, { 11, 8 }, { 11, 8 }, { 11, 8 }, + { 11, 9 }, { 9, 13 }, { 11, 10 }, { 11, 10 }, { 12, 8 }, { 12, 8 }, + { 12, 9 }, { 12, 9 }, { 12, 10 }, { 12, 10 }, { 12, 10 }, { 11, 13 }, + { 13, 9 }, { 13, 9 }, { 13, 10 }, { 12, 12 }, { 13, 11 }, { 13, 11 }, + { 13, 11 }, { 14, 10 }, { 14, 10 }, { 14, 10 }, { 14, 11 }, { 13, 13 }, + { 14, 12 }, { 14, 12 }, { 12, 16 }, { 15, 11 }, { 15, 11 }, { 15, 11 }, + { 15, 12 }, { 15, 12 }, { 15, 12 }, { 15, 13 }, { 13, 17 }, { 15, 14 }, + { 15, 14 }, { 16, 12 }, { 16, 12 }, { 16, 13 }, { 16, 13 }, { 16, 14 }, + { 16, 14 }, { 16, 14 }, { 15, 17 }, { 17, 13 }, { 17, 13 }, { 17, 14 }, + { 16, 16 }, { 17, 15 }, { 17, 15 }, { 17, 15 }, { 18, 14 }, { 18, 14 }, + { 18, 14 }, { 18, 15 }, { 17, 17 }, { 18, 16 }, { 18, 16 }, { 16, 20 }, + { 19, 15 }, { 19, 15 }, { 19, 15 }, { 19, 16 }, { 19, 16 }, { 19, 16 }, + { 19, 17 }, { 17, 21 }, { 19, 18 }, { 19, 18 }, { 20, 16 }, { 20, 16 }, + { 20, 17 }, { 20, 17 }, { 20, 18 }, { 20, 18 }, { 20, 18 }, { 19, 21 }, + { 21, 17 }, { 21, 17 }, { 21, 18 }, { 20, 20 }, { 21, 19 }, { 21, 19 }, + { 21, 19 }, { 22, 18 }, { 22, 18 }, { 22, 18 }, { 22, 19 }, { 21, 21 }, + { 22, 20 }, { 22, 20 }, { 20, 24 }, { 23, 19 }, { 23, 19 }, { 23, 19 }, + { 23, 20 }, { 23, 20 }, { 23, 20 }, { 23, 21 }, { 21, 25 }, { 23, 22 }, + { 23, 22 }, { 24, 20 }, { 24, 20 }, { 24, 21 }, { 24, 21 }, { 24, 22 }, + { 24, 22 }, { 24, 22 }, { 23, 25 }, { 25, 21 }, { 25, 21 }, { 25, 22 }, + { 24, 24 }, { 25, 23 }, { 25, 23 }, { 25, 23 }, { 26, 22 }, { 26, 22 }, + { 26, 22 }, { 26, 23 }, { 25, 25 }, { 26, 24 }, { 26, 24 }, { 24, 28 }, + { 27, 23 }, { 27, 23 }, { 27, 23 }, { 27, 24 }, { 27, 24 }, { 27, 24 }, + { 27, 25 }, { 25, 29 }, { 27, 26 }, { 27, 26 }, { 28, 24 }, { 28, 24 }, + { 28, 25 }, { 28, 25 }, { 28, 26 }, { 28, 26 }, { 28, 26 }, { 27, 29 }, + { 29, 25 }, { 29, 25 }, { 29, 26 }, { 28, 28 }, { 29, 27 }, { 29, 27 }, + { 29, 27 }, { 30, 26 }, { 30, 26 }, { 30, 26 }, { 30, 27 }, { 29, 29 }, + { 30, 28 }, { 30, 28 }, { 30, 28 }, { 31, 27 }, { 31, 27 }, { 31, 27 }, + { 31, 28 }, { 31, 28 }, { 31, 28 }, { 31, 29 }, { 31, 29 }, { 31, 30 }, + { 31, 30 }, { 31, 30 }, { 31, 31 }, { 31, 31 }, +}; + +const static uint8_t match6[256][2] = { + { 0, 0 }, { 0, 1 }, { 1, 0 }, { 1, 0 }, { 1, 1 }, { 2, 0 }, + { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 1 }, { 4, 0 }, { 4, 0 }, + { 4, 1 }, { 5, 0 }, { 5, 1 }, { 6, 0 }, { 6, 0 }, { 6, 1 }, + { 7, 0 }, { 7, 0 }, { 7, 1 }, { 8, 0 }, { 8, 1 }, { 8, 1 }, + { 8, 2 }, { 9, 1 }, { 9, 2 }, { 9, 2 }, { 9, 3 }, { 10, 2 }, + { 10, 3 }, { 10, 3 }, { 10, 4 }, { 11, 3 }, { 11, 4 }, { 11, 4 }, + { 11, 5 }, { 12, 4 }, { 12, 5 }, { 12, 5 }, { 12, 6 }, { 13, 5 }, + { 13, 6 }, { 8, 16 }, { 13, 7 }, { 14, 6 }, { 14, 7 }, { 9, 17 }, + { 14, 8 }, { 15, 7 }, { 15, 8 }, { 11, 16 }, { 15, 9 }, { 15, 10 }, + { 16, 8 }, { 16, 9 }, { 16, 10 }, { 15, 13 }, { 17, 9 }, { 17, 10 }, + { 17, 11 }, { 15, 16 }, { 18, 10 }, { 18, 11 }, { 18, 12 }, { 16, 16 }, + { 19, 11 }, { 19, 12 }, { 19, 13 }, { 17, 17 }, { 20, 12 }, { 20, 13 }, + { 20, 14 }, { 19, 16 }, { 21, 13 }, { 21, 14 }, { 21, 15 }, { 20, 17 }, + { 22, 14 }, { 22, 15 }, { 25, 10 }, { 22, 16 }, { 23, 15 }, { 23, 16 }, + { 26, 11 }, { 23, 17 }, { 24, 16 }, { 24, 17 }, { 27, 12 }, { 24, 18 }, + { 25, 17 }, { 25, 18 }, { 28, 13 }, { 25, 19 }, { 26, 18 }, { 26, 19 }, + { 29, 14 }, { 26, 20 }, { 27, 19 }, { 27, 20 }, { 30, 15 }, { 27, 21 }, + { 28, 20 }, { 28, 21 }, { 28, 21 }, { 28, 22 }, { 29, 21 }, { 29, 22 }, + { 24, 32 }, { 29, 23 }, { 30, 22 }, { 30, 23 }, { 25, 33 }, { 30, 24 }, + { 31, 23 }, { 31, 24 }, { 27, 32 }, { 31, 25 }, { 31, 26 }, { 32, 24 }, + { 32, 25 }, { 32, 26 }, { 31, 29 }, { 33, 25 }, { 33, 26 }, { 33, 27 }, + { 31, 32 }, { 34, 26 }, { 34, 27 }, { 34, 28 }, { 32, 32 }, { 35, 27 }, + { 35, 28 }, { 35, 29 }, { 33, 33 }, { 36, 28 }, { 36, 29 }, { 36, 30 }, + { 35, 32 }, { 37, 29 }, { 37, 30 }, { 37, 31 }, { 36, 33 }, { 38, 30 }, + { 38, 31 }, { 41, 26 }, { 38, 32 }, { 39, 31 }, { 39, 32 }, { 42, 27 }, + { 39, 33 }, { 40, 32 }, { 40, 33 }, { 43, 28 }, { 40, 34 }, { 41, 33 }, + { 41, 34 }, { 44, 29 }, { 41, 35 }, { 42, 34 }, { 42, 35 }, { 45, 30 }, + { 42, 36 }, { 43, 35 }, { 43, 36 }, { 46, 31 }, { 43, 37 }, { 44, 36 }, + { 44, 37 }, { 44, 37 }, { 44, 38 }, { 45, 37 }, { 45, 38 }, { 40, 48 }, + { 45, 39 }, { 46, 38 }, { 46, 39 }, { 41, 49 }, { 46, 40 }, { 47, 39 }, + { 47, 40 }, { 43, 48 }, { 47, 41 }, { 47, 42 }, { 48, 40 }, { 48, 41 }, + { 48, 42 }, { 47, 45 }, { 49, 41 }, { 49, 42 }, { 49, 43 }, { 47, 48 }, + { 50, 42 }, { 50, 43 }, { 50, 44 }, { 48, 48 }, { 51, 43 }, { 51, 44 }, + { 51, 45 }, { 49, 49 }, { 52, 44 }, { 52, 45 }, { 52, 46 }, { 51, 48 }, + { 53, 45 }, { 53, 46 }, { 53, 47 }, { 52, 49 }, { 54, 46 }, { 54, 47 }, + { 57, 42 }, { 54, 48 }, { 55, 47 }, { 55, 48 }, { 58, 43 }, { 55, 49 }, + { 56, 48 }, { 56, 49 }, { 59, 44 }, { 56, 50 }, { 57, 49 }, { 57, 50 }, + { 60, 45 }, { 57, 51 }, { 58, 50 }, { 58, 51 }, { 61, 46 }, { 58, 52 }, + { 59, 51 }, { 59, 52 }, { 62, 47 }, { 59, 53 }, { 60, 52 }, { 60, 53 }, + { 60, 53 }, { 60, 54 }, { 61, 53 }, { 61, 54 }, { 61, 54 }, { 61, 55 }, + { 62, 54 }, { 62, 55 }, { 62, 55 }, { 62, 56 }, { 63, 55 }, { 63, 56 }, + { 63, 56 }, { 63, 57 }, { 63, 58 }, { 63, 59 }, { 63, 59 }, { 63, 60 }, + { 63, 61 }, { 63, 62 }, { 63, 62 }, { 63, 63 }, +}; + +/* Multiplication over 8 bit emulation */ +#define mul8(a, b) (a * b + 128 + ((a * b + 128) >> 8)) >> 8 + +/* Conversion from rgb24 to rgb565 */ +#define rgb2rgb565(r, g, b) \ + (mul8(r, 31) << 11) | (mul8(g, 63) << 5) | (mul8(b, 31) << 0) + +/* Linear interpolation at 1/3 point between a and b */ +#define lerp13(a, b) (2 * a + b) / 3 + +/* Linear interpolation on an RGB pixel */ +static inline void lerp13rgb(uint8_t *out, uint8_t *p1, uint8_t *p2) +{ + out[0] = lerp13(p1[0], p2[0]); + out[1] = lerp13(p1[1], p2[1]); + out[2] = lerp13(p1[2], p2[2]); +} + +/* Conversion from rgb565 to rgb24 */ +static inline void rgb5652rgb(uint8_t *out, uint16_t v) +{ + int rv = (v & 0xf800) >> 11; + int gv = (v & 0x07e0) >> 5; + int bv = (v & 0x001f) >> 0; + + out[0] = expand5[rv]; + out[1] = expand6[gv]; + out[2] = expand5[bv]; + out[3] = 0; +} + +/* Color matching function */ +static unsigned int match_colors(const uint8_t *block, ptrdiff_t stride, + uint16_t c0, uint16_t c1) +{ + uint32_t mask = 0; + int dirr, dirg, dirb; + int dots[16]; + int stops[4]; + int x, y, k = 0; + int c0_point, half_point, c3_point; + uint8_t color[16]; + const int indexMap[8] = { + 0 << 30, 2 << 30, 0 << 30, 2 << 30, + 3 << 30, 3 << 30, 1 << 30, 1 << 30, + }; + + /* Fill color and compute direction for each component */ + rgb5652rgb(color + 0, c0); + rgb5652rgb(color + 4, c1); + lerp13rgb(color + 8, color + 0, color + 4); + lerp13rgb(color + 12, color + 4, color + 0); + + dirr = color[0 * 4 + 0] - color[1 * 4 + 0]; + dirg = color[0 * 4 + 1] - color[1 * 4 + 1]; + dirb = color[0 * 4 + 2] - color[1 * 4 + 2]; + + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) + dots[k++] = block[0 + x * 4 + y * stride] * dirr + + block[1 + x * 4 + y * stride] * dirg + + block[2 + x * 4 + y * stride] * dirb; + + stops[y] = color[0 + y * 4] * dirr + + color[1 + y * 4] * dirg + + color[2 + y * 4] * dirb; + } + + /* Think of the colors as arranged on a line; project point onto that line, + * then choose next color out of available ones. we compute the crossover + * points for 'best color in top half'/'best in bottom half' and then + * the same inside that subinterval. + * + * Relying on this 1d approximation isn't always optimal in terms of + * euclidean distance, but it's very close and a lot faster. + * + * http://cbloomrants.blogspot.com/2008/12/12-08-08-dxtc-summary.html */ + c0_point = (stops[1] + stops[3]) >> 1; + half_point = (stops[3] + stops[2]) >> 1; + c3_point = (stops[2] + stops[0]) >> 1; + + for (x = 0; x < 16; x++) { + int dot = dots[x]; + int bits = (dot < half_point ? 4 : 0) | + (dot < c0_point ? 2 : 0) | + (dot < c3_point ? 1 : 0); + + mask >>= 2; + mask |= indexMap[bits]; + } + + return mask; +} + +/* Color optimization function */ +static void optimize_colors(const uint8_t *block, ptrdiff_t stride, + uint16_t *pmax16, uint16_t *pmin16) +{ + const uint8_t *minp; + const uint8_t *maxp; + const int iter_power = 4; + double magn; + int v_r, v_g, v_b; + float covf[6], vfr, vfg, vfb; + int mind, maxd; + int cov[6] = { 0 }; + int mu[3], min[3], max[3]; + int ch, iter, x, y; + + /* Determine color distribution */ + for (ch = 0; ch < 3; ch++) { + const uint8_t *bp = &block[ch]; + int muv, minv, maxv; + + muv = minv = maxv = bp[0]; + for (y = 0; y < 4; y++) { + for (x = 4; x < 4; x += 4) { + muv += bp[x * 4 + y * stride]; + if (bp[x] < minv) + minv = bp[x * 4 + y * stride]; + else if (bp[x] > maxv) + maxv = bp[x * 4 + y * stride]; + } + } + + mu[ch] = (muv + 8) >> 4; + min[ch] = minv; + max[ch] = maxv; + } + + /* Determine covariance matrix */ + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + int r = block[x * 4 + stride * y + 0] - mu[0]; + int g = block[x * 4 + stride * y + 1] - mu[1]; + int b = block[x * 4 + stride * y + 2] - mu[2]; + + cov[0] += r * r; + cov[1] += r * g; + cov[2] += r * b; + cov[3] += g * g; + cov[4] += g * b; + cov[5] += b * b; + } + } + + /* Convert covariance matrix to float, find principal axis via power iter */ + for (x = 0; x < 6; x++) + covf[x] = cov[x] / 255.0f; + + vfr = (float) (max[0] - min[0]); + vfg = (float) (max[1] - min[1]); + vfb = (float) (max[2] - min[2]); + + for (iter = 0; iter < iter_power; iter++) { + float r = vfr * covf[0] + vfg * covf[1] + vfb * covf[2]; + float g = vfr * covf[1] + vfg * covf[3] + vfb * covf[4]; + float b = vfr * covf[2] + vfg * covf[4] + vfb * covf[5]; + + vfr = r; + vfg = g; + vfb = b; + } + + magn = fabs(vfr); + if (fabs(vfg) > magn) + magn = fabs(vfg); + if (fabs(vfb) > magn) + magn = fabs(vfb); + + /* if magnitudo is too small, default to luminance */ + if (magn < 4.0f) { + /* JPEG YCbCr luma coefs, scaled by 1000 */ + v_r = 299; + v_g = 587; + v_b = 114; + } else { + magn = 512.0 / magn; + v_r = (int) (vfr * magn); + v_g = (int) (vfg * magn); + v_b = (int) (vfb * magn); + } + + /* Pick colors at extreme points */ + mind = maxd = block[0] * v_r + block[1] * v_g + block[2] * v_b; + minp = maxp = block; + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + int dot = block[x * 4 + y * stride + 0] * v_r + + block[x * 4 + y * stride + 1] * v_g + + block[x * 4 + y * stride + 2] * v_b; + + if (dot < mind) { + mind = dot; + minp = block + x * 4 + y * stride; + } else if (dot > maxd) { + maxd = dot; + maxp = block + x * 4 + y * stride; + } + } + } + + *pmax16 = rgb2rgb565(maxp[0], maxp[1], maxp[2]); + *pmin16 = rgb2rgb565(minp[0], minp[1], minp[2]); +} + +/* Try to optimize colors to suit block contents better, by solving + * a least squares system via normal equations + Cramer's rule. */ +static int refine_colors(const uint8_t *block, ptrdiff_t stride, + uint16_t *pmax16, uint16_t *pmin16, uint32_t mask) +{ + uint32_t cm = mask; + uint16_t oldMin = *pmin16; + uint16_t oldMax = *pmax16; + uint16_t min16, max16; + int x, y; + + /* Additional magic to save a lot of multiplies in the accumulating loop. + * The tables contain precomputed products of weights for least squares + * system, accumulated inside one 32-bit register */ + const int w1tab[4] = { 3, 0, 2, 1 }; + const int prods[4] = { 0x090000, 0x000900, 0x040102, 0x010402 }; + + /* Check if all pixels have the same index */ + if (mask ^ (mask << 2) < 4) { + /* If so, linear system would be singular; solve using optimal + * single-color match on average color. */ + int r = 8, g = 8, b = 8; + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + r += block[0 + x * 4 + y * stride]; + g += block[1 + x * 4 + y * stride]; + b += block[2 + x * 4 + y * stride]; + } + } + + r >>= 4; + g >>= 4; + b >>= 4; + + max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0]; + min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1]; + } else { + float fr, fg, fb; + int at1_r = 0, at1_g = 0, at1_b = 0; + int at2_r = 0, at2_g = 0, at2_b = 0; + int akku = 0; + int xx, xy, yy; + + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + int step = cm & 3; + int w1 = w1tab[step]; + int r = block[0 + x * 4 + y * stride]; + int g = block[1 + x * 4 + y * stride]; + int b = block[2 + x * 4 + y * stride]; + + akku += prods[step]; + at1_r += w1 * r; + at1_g += w1 * g; + at1_b += w1 * b; + at2_r += r; + at2_g += g; + at2_b += b; + + cm >>= 2; + } + } + + at2_r = 3 * at2_r - at1_r; + at2_g = 3 * at2_g - at1_g; + at2_b = 3 * at2_b - at1_b; + + /* Extract solutions and decide solvability */ + xx = akku >> 16; + yy = (akku >> 8) & 0xFF; + xy = (akku >> 0) & 0xFF; + + fr = 3.0f * 31.0f / 255.0f / (xx * yy - xy * xy); + fg = fr * 63.0f / 31.0f; + fb = fr; + + /* Solve */ + max16 = av_clip_uintp2((at1_r * yy - at2_r * xy) * fr + 0.5f, 5) << 11; + max16 |= av_clip_uintp2((at1_g * yy - at2_g * xy) * fg + 0.5f, 6) << 5; + max16 |= av_clip_uintp2((at1_b * yy - at2_b * xy) * fb + 0.5f, 5) << 0; + + min16 = av_clip_uintp2((at2_r * xx - at1_r * xy) * fr + 0.5f, 5) << 11; + min16 |= av_clip_uintp2((at2_g * xx - at1_g * xy) * fg + 0.5f, 6) << 5; + min16 |= av_clip_uintp2((at2_b * xx - at1_b * xy) * fb + 0.5f, 5) << 0; + } + + *pmin16 = min16; + *pmax16 = max16; + return oldMin != min16 || oldMax != max16; +} + +/* Check if input block is a constant color */ +static int constant_color(const uint8_t *block, ptrdiff_t stride) +{ + int x, y; + uint32_t first = AV_RL32(block); + + for (y = 0; y < 4; y++) + for (x = 0; x < 4; x++) + if (first != AV_RL32(block + x * 4 + y * stride)) + return 0; + return 1; +} + +/* Main color compression function */ +static void compress_color(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) +{ + uint32_t mask; + uint16_t max16, min16; + int constant = constant_color(block, stride); + + /* Constant color will load values from tables */ + if (constant) { + int r = block[0]; + int g = block[1]; + int b = block[2]; + mask = 0xAAAAAAAA; + max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0]; + min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1]; + } else { + int refine; + + /* Otherwise find pca and map along principal axis */ + optimize_colors(block, stride, &max16, &min16); + if (max16 != min16) + mask = match_colors(block, stride, max16, min16); + else + mask = 0; + + /* One pass refinement */ + refine = refine_colors(block, stride, &max16, &min16, mask); + if (refine) { + if (max16 != min16) + mask = match_colors(block, stride, max16, min16); + else + mask = 0; + } + } + + /* Finally write the color block */ + if (max16 < min16) { + FFSWAP(uint16_t, min16, max16); + mask ^= 0x55555555; + } + + AV_WL16(dst + 0, max16); + AV_WL16(dst + 2, min16); + AV_WL32(dst + 4, mask); +} + +/* Alpha compression function */ +static void compress_alpha(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) +{ + int x, y; + int dist, bias, dist4, dist2; + int mn, mx; + int bits = 0; + int mask = 0; + + memset(dst, 0, 8); + + /* Find min/max color */ + mn = mx = block[3]; + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + int val = block[3 + x * 4 + y * stride]; + if (val < mn) + mn = val; + else if (val > mx) + mx = val; + } + } + + /* Encode them */ + dst[0] = (uint8_t) mx; + dst[1] = (uint8_t) mn; + dst += 2; + + /* Mono-alpha shortcut */ + if (mn == mx) + return; + + /* Determine bias and emit color indices. + * Given the choice of mx/mn, these indices are optimal: + * fgiesen.wordpress.com/2009/12/15/dxt5-alpha-block-index-determination */ + dist = mx - mn; + + dist4 = dist * 4; + dist2 = dist * 2; + if (dist < 8) + bias = dist - 1 - mn * 7; + else + bias = dist / 2 + 2 - mn * 7; + + for (y = 0; y < 4; y++) { + for (x = 0; x < 4; x++) { + int alp = block[3 + x * 4 + y * stride] * 7 + bias; + int ind, tmp; + + /* This is a "linear scale" lerp factor between 0 (val=min) + * and 7 (val=max) to select index. */ + tmp = (alp >= dist4) ? -1 : 0; + ind = tmp & 4; + alp -= dist4 & tmp; + tmp = (alp >= dist2) ? -1 : 0; + ind += tmp & 2; + alp -= dist2 & tmp; + ind += (alp >= dist); + + /* Turn linear scale into DXT index (0/1 are extreme points) */ + ind = -ind & 7; + ind ^= (2 > ind); + + /* Write index */ + mask |= ind << bits; + bits += 3; + if (bits >= 8) { + *dst++ = mask; + mask >>= 8; + bits -= 8; + } + } + } +} + +/** + * Convert a RGBA buffer to unscaled YCoCg. + * Scale is usually introduced to avoid banding over a certain range of colors, + * but this version of the algorithm does not introduce it as much as other + * implementations, allowing for a simpler and faster conversion. + */ +static void rgba2ycocg(uint8_t *dst, const uint8_t *pixel) +{ + int r = pixel[0]; + int g = (pixel[1] + 1) >> 1; + int b = pixel[2]; + int t = (2 + r + b) >> 2; + + int y = av_clip_uint8(g + t); + int co = av_clip_uint8(128 + ((r - b + 1) >> 1)); + int cg = av_clip_uint8(128 + g - t); + + dst[0] = (uint8_t) co; + dst[1] = (uint8_t) cg; + dst[2] = 0; + dst[3] = (uint8_t) y; +} + +/** + * Compress one block of RGBA pixels in a DXT1 texture and store the + * resulting bytes in 'dst'. Alpha is not preserved. + * + * @param dst output buffer. + * @param stride scanline in bytes. + * @param block block to compress. + * @return how much texture data has been written. + */ +static int dxt1_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) +{ + compress_color(dst, stride, block); + + return 8; +} + +/** + * Compress one block of RGBA pixels in a DXT5 texture and store the + * resulting bytes in 'dst'. Alpha is preserved. + * + * @param dst output buffer. + * @param stride scanline in bytes. + * @param block block to compress. + * @return how much texture data has been written. + */ +static int dxt5_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) +{ + compress_alpha(dst, stride, block); + compress_color(dst + 8, stride, block); + + return 16; +} + +/** + * Compress one block of RGBA pixels in a DXT5-YCoCg texture and store the + * resulting bytes in 'dst'. Alpha is not preserved. + * + * @param dst output buffer. + * @param stride scanline in bytes. + * @param block block to compress. + * @return how much texture data has been written. + */ +static int dxt5ys_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) +{ + int x, y; + uint8_t reorder[64]; + + /* Reorder the components and then run a normal DXT5 compression. */ + for (y = 0; y < 4; y++) + for (x = 0; x < 4; x++) + rgba2ycocg(reorder + x * 4 + y * 16, block + x * 4 + y * stride); + + compress_alpha(dst + 0, 16, reorder); + compress_color(dst + 8, 16, reorder); + + return 16; +} + +av_cold void ff_texturedspenc_init(TextureDSPContext *c) +{ + c->dxt1_block = dxt1_block; + c->dxt5_block = dxt5_block; + c->dxt5ys_block = dxt5ys_block; +} -- cgit v1.2.3